ZF-ECOLIFE-适用于城市公共汽车的、现代化的动力换档变速器

ZF-ECOLIFE-THE DEVELOPMENT OF A MODERN POWERSHIFT TRANSMISSION FOR CITY BUSES

除了内燃机和车桥系统外,道路车辆的传动系统主要由变速器所决定。目前城市公共汽车中主要采用动力换档的自动变速器,特别是因为它们具有舒适性高和操纵便捷的特点。今天变速器系统的新挑战源自于内燃机的改进,特别是受制于排放法规使得内燃机提高转矩和冷却温度。另一方面,车辆的全寿命成本正变得更加重要,并由此带来技术方面的挑战,例如更高的可靠性和更佳的燃油经济性等。将诸如成本、舒适性最优等各种要求合并,形成了相当复杂的需求内容。而且这些需求对车辆制造商和诸如操作人员的最终用户有所不同。因此ZF公司开发新一代动力换档变速器,将长期目标与诸如更广的车辆应用场合、降低全寿命成本、简化使用条件等用户需求相结合。采用QFD(质量功能展开)方法分析后发现,由液力变矩器、行星齿轮机构和初级缓速器组成的动力换档变速器是满足各种不同需求的最佳方案。我们开发的新变速器在设计和制造的各个细节方面均采用了特殊和全新的解决方案。将最新的开发工具和方法应用与概念定义中。最终形成的动力换档变速器是一个6档行星齿轮变速器、带锁止离合器的液力变矩器,并可选装扭转减振器。新的冷却系统有两个热交换器,以提高系统的可靠性和改善城市公共汽车初级缓速器的制动转矩以适应更重的车辆、较高平均速度、长时间性能和舒适性等方面的要求。新型ECU直接安装在变速器上,其电气安装界面做到最小。其结论是,新型动力换档变速器的优势非常突出,因为它们体现了当代和今后动力传动系统应有的高性能,以及更佳的全寿命成本和优越的舒适性;并且在安全性和环保方面都相当出色。最后强调一下,我们将其取名为EcoLife,象征着更高的经济性和生态效益以及寿命。

Apart from the internal combustion engine and the axle system, the driveline of a road vehicle is priraarily defined by the transmission. In today＇s city buses powershift automatic transmissions are predominantly used, especially due to their high level of comfort and easy operation. New challenges for transmission systems of today are originated by the improvements of the combustion engines, especially their increasing torque and coolant temperatures, which are driven by emission regulations. On the other hand, life cycle cost for the vehicle systems are getting more and more important and lead to technological challenges, e.g. higher reliability and better fuel consumption. In conjunction with overall requirements like optimum cost, comfort etc. , this leads to a very complex spectrum of requirements. These demands are partly differ- ent for vehicle manufacturers and end users like line operators, respectively. As a consequence, we started the development of a new powershift transmission, which was aligned with long-term targets, strongly oriented on customer＇s demands, e.g. more comprehensive vehicle applications, reduced life cycle costs, and reduced application efforts required. After a general analysis with the QFD methodology （quality function deployment）, the transmission type, a powershift transmission with torque converter, planetary gear set, and primary retarder was found to be the adequate solution to the multiple and diverging requirements. We developed a transmission system which offers specific and new solutions in all of its design and manufactur- ing details. Latest development tools and methods, which are briefly described, were used to define the concept. The result is a modular powershift transmission with a 6-speed planetary gear set; it features a torqueconverter with lock-up clutch and optional torsional vibration damper. The new powerful cooling system is equipped with two heat exchangers, providing the unit with a high level of reliability and improved braking torque for heavier buses as well as higher average speeds, long-term performance, and comfort for the primary city bus retarder. The modern ECU is directly mounted to the transmission which generated a minimum number of electrical interfaces. As a conclusion, the advantages of the new powershift transmissions are highlighted because they represent a higher level of performance/or today＇s and future powertrains, as well as improved life cycle costs and excellent comfort; moreover, they excel thanks to additional safety characteristics and the respective environmental protection contributions. To emphasize this, we named it EcoLife, which stands for both, higher economical and ecological benefits as well as improved lifetime.